Hello,
I made a GUI in processing some time ago. The application itself can be used to draw a schematic for a modelrailway. This schematic is stored and loaded to and from CSV files.
I know very little about modern webserver stuff.
I would like this sketch to run on a raspberry pi as a web server. I want to be able to use any computer with any webbrowser to interact with the application as a client.
Besides storing a layout on a CSV file, the content also needs to be sent via a serial port to an arduino board. As a standalone executable this all works fine, but now I want to use a client pc.
I have read a little about javascript. But this is mostly new to me. I do C, C++, python and a bit java, but that’s about it…
I do have some experience with running a server with a processing sketch. (with an wemos D1 mini as client) 
I tested the example and firefox could open and ‘play’ the .html file on my PC.
But how do I host that .html file as a webserver? Before I use the raspberry I would like to host this .html on my windows 10 PC. I can than use my smartphone or other PC with a browser to test.
Can I for instance make a webserver with a processing sketch and copy/paste the content of that html file inside that sketch?
Obviously my own application exists out of many .pde files. How exactly do I stuff that in a .html file?
Any pointers would be appreciated,
Bas